Initial QSfera import

Server/vendor/github.com/opencloud-eu/reva/v2/pkg/logger/logger.go

@@ -0,0 +1,165 @@
+// Copyright 2018-2021 CERN
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// In applying this license, CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+package logger
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"time"
+
+	"github.com/mitchellh/mapstructure"
+	"github.com/pkg/errors"
+	"github.com/rs/zerolog"
+)
+
+func init() {
+	zerolog.CallerSkipFrameCount = 2
+	zerolog.TimeFieldFormat = time.RFC3339Nano
+}
+
+// Mode changes the logging format.
+type Mode string
+
+const (
+	// JSONMode outputs JSON.
+	JSONMode Mode = "json"
+	// ConsoleMode outputs human-readable logs.
+	ConsoleMode Mode = "console"
+)
+
+// Option is the option to use to configure the logger.
+type Option func(l *zerolog.Logger)
+
+// New creates a new logger.
+func New(opts ...Option) *zerolog.Logger {
+	// create a default logger
+	zerolog.SetGlobalLevel(zerolog.TraceLevel)
+	zl := zerolog.New(os.Stderr).With().Timestamp().Caller().Logger()
+	for _, opt := range opts {
+		opt(&zl)
+	}
+	return &zl
+}
+
+// WithLevel is an option to configure the logging level.
+func WithLevel(lvl string) Option {
+	return func(l *zerolog.Logger) {
+		zlvl := parseLevel(lvl)
+		*l = l.Level(zlvl)
+	}
+}
+
+// WithWriter is an option to configure the logging output.
+func WithWriter(w io.Writer, m Mode) Option {
+	return func(l *zerolog.Logger) {
+		if m == ConsoleMode {
+			*l = l.Output(zerolog.ConsoleWriter{Out: w, TimeFormat: "2006-01-02 15:04:05.999"})
+		} else {
+			*l = l.Output(w)
+		}
+	}
+}
+
+func parseLevel(v string) zerolog.Level {
+	if v == "" {
+		return zerolog.InfoLevel
+	}
+
+	lvl, err := zerolog.ParseLevel(v)
+	if err != nil {
+		return zerolog.InfoLevel
+	}
+
+	return lvl
+}
+
+func InitLoggerOrDie(v interface{}, logLevel string) *zerolog.Logger {
+	conf := ParseLogConfOrDie(v, logLevel)
+	log, err := fromConfig(conf)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error creating logger, exiting ...")
+		os.Exit(1)
+	}
+	return log
+}
+
+func ParseLogConfOrDie(v interface{}, logLevel string) *LogConf {
+	c := &LogConf{}
+	if err := mapstructure.Decode(v, c); err != nil {
+		fmt.Fprintf(os.Stderr, "error decoding log config: %s\n", err.Error())
+		os.Exit(1)
+	}
+
+	// if mode is not set, we use console mode, easier for devs
+	if c.Mode == "" {
+		c.Mode = "console"
+	}
+
+	// Give priority to the log level passed through the command line.
+	if logLevel != "" {
+		c.Level = logLevel
+	}
+
+	return c
+}
+
+type LogConf struct {
+	Output string `mapstructure:"output"`
+	Mode   string `mapstructure:"mode"`
+	Level  string `mapstructure:"level"`
+}
+
+func fromConfig(conf *LogConf) (*zerolog.Logger, error) {
+	if conf.Level == "" {
+		conf.Level = zerolog.InfoLevel.String()
+	}
+
+	var opts []Option
+	opts = append(opts, WithLevel(conf.Level))
+
+	w, err := getWriter(conf.Output)
+	if err != nil {
+		return nil, err
+	}
+
+	opts = append(opts, WithWriter(w, Mode(conf.Mode)))
+
+	l := New(opts...)
+	sub := l.With().Int("pid", os.Getpid()).Logger()
+	return &sub, nil
+}
+
+func getWriter(out string) (io.Writer, error) {
+	if out == "stderr" || out == "" {
+		return os.Stderr, nil
+	}
+
+	if out == "stdout" {
+		return os.Stdout, nil
+	}
+
+	fd, err := os.OpenFile(out, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0o644)
+	if err != nil {
+		err = errors.Wrap(err, "error creating log file: "+out)
+		return nil, err
+	}
+
+	return fd, nil
+}